1. Field of the Invention
The present invention relates to a vibrator, a vibration type driving apparatus and a manufacturing method of the vibrator.
2. Description of the Related Art
Conventionally, a vibration type driving apparatus (for example, ultrasonic motor) that drives a moving body by vibration generated by an elastic body is known.
In the vibration type driving apparatus, a vibrator that includes an electrical-mechanical energy converting element (for example, piezoelectric element) and an elastic body (elastic body mainly made of metal) bonded with the electrical-mechanical energy converting element excites a plurality of vibration modes.
The plurality of vibrations are combined to generate an elliptical motion on a surface of the elastic body, and a member to be driven that is in contact with the elastic body is relatively driven.
Various forms of the vibration type driving apparatus are proposed. For example, in relation to a vibration wave motor that rotates and drives a lens barrel of a camera, a ring-shaped vibration wave motor and a rod-shaped rotary vibration wave motor are proposed.
A large number of devised motor configurations and forms are further proposed, such as a vibration wave motor formed as a rotary actuator including a plurality of plate-shaped elastic bodies on the circumference, in which a vibrating part is formed by a thin plate part and a projection part.
A large number of linear type vibration wave motors are also proposed, in which the plate type elastic bodies come into contact with a linear slider to linearly drive the elastic bodies.
A vibration type driving apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-304887 will be illustrated as an example to describe a summary of a configuration of the vibration wave motor including the plate type elastic body.
The vibration type driving apparatus includes a vibrator and a slider that comes into contact with the vibrator.
The vibrator is formed by bonding an electrical-mechanical energy converting element (for example, piezoelectric element) to a plate type elastic body including a flat-plate vibrating body provided with two projection parts on one of the surfaces.
If AC electric fields at different phases are applied to the piezoelectric element, two out-of-plane bending vibrations are excited in the vibrator, and an elliptical motion is generated at tips of the two projection parts.
As a result, the slider that comes into contact with the projection parts receives frictional driving force and is driven in one direction.